Here's why:

* Tissues are groups of similar cells that work together to perform a specific function.

* Organisms are classified into different levels of organization, with some being simpler than others.

Organisms without tissues:

* Prokaryotes: These are single-celled organisms like bacteria and archaea. They lack the complex internal organization necessary for tissues.

* Simple Multicellular Organisms: Some multicellular organisms, like sponges, are considered "tissue-less". Their cells are specialized but not organized into distinct tissues. They rely on direct cell-to-cell communication for coordination.

Organisms with tissues:

* Plants and Animals: Most multicellular organisms, including plants and animals, have tissues. These tissues are further organized into organs and organ systems, allowing for more complex functions and body plans.

In short, the presence of tissues is a characteristic of complex multicellular organisms, but not a universal feature of all life.